Relation of the Viscosity to the Hearing Level in Otitis Media with Effusion

Abstract

In order to measure the viscosity of amounts of material as small as 0.05 ml, we developed a new viscosimeter. With this system the lower plate is rotated constantly, then the torque that is the force impelling the upper plate to rotate, and the upward thrust are measured. Using this device, the viscosity of stagnant exudate from otitis media was measured to investigate the relation between viscosity of stagnant middle ear and degree of improvement in hearing. Middle ear effusions were obtained from cases of exudative otitis media. This study was conducted in 23 ears of 21 cases (male 11, female 10 aged from 2 to 78 years). We also expressed the viscosity from 1 to 5 through the diameter of the tube, through which the exudate was aspirated. Viscosity (mPa・s) of the middle ear fluid was measured using the viscosimeter. Before and after the operation we measured audiograms. We could not find any relation between the result of viscosity measured with the viscosimeter and the simplified aspiration method. The viscosity of the exudate and the degree of improvement in hearing were highly correlated significantly